Chlorination of 1-vinylcyclohexene-3



Patented Aug. 8, 1950 Micron-04f;

Herbert "Li. ..f.t-di1asn; 7 Media, Land Archibaid" r.

Stuart, Norwood, Pfa., assignorst SunQiLCmne "pany, Philadelphia, Pa., a corporationofNew,

Jersey This invention relates to the chlorinationot-L; vinyl-cyclohexene-3 and to chlorination prod l ts obtained thereby. I

According to t-h'e'invention novel coinpounds for example, vinylcyclohexene dichloridesfl and; vinylcyclohexene tetrachloride, cang-bejpprepared. by the chlorination of levinylcyclohexene--un der conditions hereinafter described. The nature and the amount of any particular compound formed can be controlled to a considerable extent under conditions hereinafter specified.

As stated, the compounds formed, according, to. the invention are chlorinated 'derivativesisof lievinylcyclohexene-3. Hereinan'd in thetclaimrthe. term vinylcyclohexene refers to l-vinylcyclo: hexene-'3 only. The dich'lorides of vinylcyclohexene, obtained upon chlorination of vinylcyclohexene as hereinafter described are two in number. For convenience, reference to these derivatives will. be: made as follows: the alpha dichloride of vinylcyclohexene? is the dichloride which has the lowerboiling point and contains the chlorine in the ring; the, beta dichloride of vinylcyclohexene is the "dichloride .whichha's the higher boiling point and contains the'chlo'rine in the side chain. The tetrachloride is, of course, that compound of vinylcyclohexene in which iour chlorine atoms have beenattach ed; .two to; the ring and two to the side chain or vinyl group, e. g. 1 1,13 dichloroethyl) 3,4 dichloro'cycloe hexane. v Another chlorinated derivative 61 vinylcyclo hexene found to have been prepared when chlorinating vinylcyclohexene, according to the invention, under the hereinafter described conditions, appears to be monochlorovinylcyclohexene. As employed herein and in the appended claim the terms monochlorovinylcyclohexene and monochloro compound are that compound which can be considered derived from vinylcyclohexene by replacing a hydrogen atom in vinylcyclohexene.

Monochlorovinylcyclohexene appears to be formed by the substitution of a hydrogen atom in the ring by a chlorine atom. The boiling point and chlorine analysis appear to confirm the composition of monochlorovinylcyclohexene at least to the extent that the two double bonds of vinylcyclohexene appear not to have been saturated.

m ttin liiiaplicatien mryrro, 1946-, SergiaLNo. 682,598 s= l glaim ,(ol. e e 9348)" renewing tabulation lists some of the properties of the compounds of the invention.

I p Per Cent 01 are 3' minin A r Cale. .Found mndmcmvcn "68". 13 r4965v 24187 25.06 vane-mon xide 61-3 2 1.4993 39.58. 39.39 Von flxliciilorid'e 70 112- 1.5043 39.58: 40.02 .VCH tetrachloride. 107-9 0. 4 1. 5255 55. 43 56. 6;

As stated the compounds'of the invention are prepared by' chlorination of vinylcyclohexene. The chlorination of vinylcyclohexenewas. effected in substantially anhydrous liquid phase GIIXPIOYF' tug. usuallaboratory equipment and technique-.- Howe-venit was discovered upon performing. the, chlorination under different conditions thatde pending upon the conditions selected it is possibleto obtain any of the desired chlorinated derivaf tivesin quantities enabling practical separation from the reaction mixture. Exclusive of the preparation-of the tetrachloride which has been foundto: be relatively simple, it has been dis-- covered possible to prepare the alpha-dichloride in quantities predominating the beta-dichloride with the exclusion of the formation of the mono- ChlQFO compound. 5 Thus, it has been discovered that the lower the temperature the. greater will be the ratio oi alpha-dichloride tobeta-dichloride. For example, at a chlorination temperature inthe neighborhood of about 0., say 60 0., this ratio is about 4 to 1. At 0 0. this ratio is about 1 to 1. At 20 C. the quantities of alphadichloride and beta-dichloride formed are about equal. Thus, unexpectedlyv it is possible to chlorinate vinylcyclohexene to prepare one of the two dichlorides in predominant amounts. The monochloro compound, discovered to be formed at higher temperatures, is not formed at lower temperatures, say below minus 30 C. Therefore, according to the invention there is provided a process for the preparation of predominant quantities of alpha-dichloride by chlorinating vinylcyclohexene at low temperatures in the range 80 C. to about 15 0., preferably in the neighborhood of 60 C.

As the temperature is increased it has been discovered that the quantity of the monochloro compound formed in the mixture of chlorides tends to equal the quantity or quantities of each of the alpha-dichloride and beta-dichloride. Thus at higher temperatures, say up to about 130 C., the boiling point of vinylcyclohexene, it is possible to form substantial quantities of the monochloro compound, while at temperatures of about 30 C. only a trace is obtained.

Therefore, according to the invention, there is provided a process for the preparation of a mixture of the monochloro compound, the dichlorides and the tetrachloride which is formed at all temperatures recited.

The rate at which the chlorine is passed into the vinylcyclohexene can readily be determined by one skilled in the art knowing that the chlorination can be made to proceed. However, it is to be noted that, with the usual laboratory equipment employed, rates substantially above 1 gram/minute/mol vinylcyclohexene would yield no practical result at zero C. At lower temperatures the rate can be increased somewhat. Best results have been obtained with rates of about 0.3 gram/minute/mol vinylcyclohexene.

The use of a solvent for vinylclohexene has been found to increase control and therefore the yield of thedesired products. Solvents employed have been chlorinated hydrocarbons and carbon disulfide. Other solvents are not excluded from the scope of the invention. These should, of course, not react with vinylcyclohexene or with chlorine to form undesirable compounds. The following examples serve to further illustrate the methods and compounds of the invention.

Example I One mo] of vinylcyclohexene was dissolved in an"e'qual volume of carbon tetrachloride, and cooled to C. whilechlorine (1 mol) was added at the rate of 0.25 gram per minute. The prodnot" was washed with water and 5% sodium bicarbonate" and dried over anhydrous calcium chloride. The solvent was distilled off, and the residue fractionated under reduced pressure. There was obtained:

33 .2% of unconverted vinylcyclohexene 12.2%: of monochlorovinylcyclohexene, B. P. 70 '''C. (18 mm.)

21% of vinylcyclohexene a-dichloride, B. P. 61-3 C. (2 mm.) 15.9% of vinylcyclohexene ,B-dichloride, B. P. 70 C. (1.2mm)

17.7% of 'vinylcyclohexene tetrachloride, B. P. "F a o-101 (1 mm.)

with a total recovery of 85 Example II Another run was made under analogous conditions, except that 2 mols of chlorine were added, yielding the following results:

with a total recovery of 81.5%.

Example III In a runat 60 C., 2 mols of chlorine were added to 2 mols of vinylcyclohexene at a rate of 0.28 gram per minute. The products obtained were as follows:

45.0% unchanged vinylcyclohexene 0.0% monochlorovinylcyclohexene ,,17.2% vinylcyclohexene alpha-dichloride 4.5% vinylcyclohexene beta-dichloride 33.3 vinylcyclohexene tetrachloride with'a total recovery of 91.5%.

The compounds of the invention appear to haveu'se as plasticizers.

From the foregoing it. will be evident that 'wide variation within the scope of the invention and the appended claim is possible. The essence of the invention is that methods for preparing novel compounds of vinylcyclohexene have been discovered and the novel compounds prepared.

='='-We claim:

A' process for the preparation'of monochlorovinylcyclohexene which comprises introducing gaseous chlorine into a solution of l-vinylcycloheXen'e-B in an inert solvent at a temperature of from about 0 C. to C., and. separating monochlorovinylcyclohexene from the reaction mixture.

- I HERBERT L. JOHNSON.

ARCHIBALD P. STUART.

REFERENCES CITED The following references are of record in the me of "this patent:

' FOREIGN PATENTS Number Country Date 268,722 C Germany Dec. 29, 1913 Society Journal," 

